Drum-forming machine



June'9, 1925.

' F. F. BACKSTROM DR-UM FORMING MACHINE Filed Sept. 15, 1925 (Fi s, 2 713 31 JASL . rod broken off.

Patented June 9, 1925.

UNJETED sr rEs AT T;

rnInoLr r. BACKSTROM, OF CHICAGO, ILLINOIS DRUM-FORMING MACHINE.

Application filed September 15', 1923'. SerialNo. 662,994.

inafter described in detail, illustrated in the accompanying drawing and more particularly pointed out in tl e appended claims.

in the drawing- Figure 1 is an edge view of a machine embodying my invention. I

Figure 2 is a face view of same with the su 3 aortinc' stand omitted and the eratin o b Figure 3 is a vertical section taken substantially on the line 33 of Figure 2.

In the several views 2 represents a vertical plate or casting with afoot portion 2 and back-bracing or strengthening ribs 3 and 4.

Said plate is cast with an anvil portion 5 which engages the inner periphery of an upper portion of the cylindrical portion of the riddle, while a similar lower anvil. portion 6 serves as a supporting shelf upon which the lower portion of said riddle'rests, the dotted lines in Figure 1 indicating the changed position of the riddle when it is nailed from the inside against the lower anvil portion 6. The upper anvil portion 5 and its plate 2 are cast with supporting ribs T and 8 which project at right angles from said plate and anvil portion. Lower down another projection on plate 2 is in the form of a bearing lug 9 through which extends a vertical bore 10 which is slidably engaged by a pull-rod 11 which may be conveniently actuated by meansof a treadle 12 that is fulcrumed at 13 to a leg or other fixed part of the bench, table or stand on which the machine is mounted, and pivoted to the rod at 14. The rod 11 is bent rearwardly'at 15, the rearward bent or inclined portion thereof passing through an opening 11 in the plate 2 and then rebent into parallelism with its upper portion as at 16 and extending down to the treadle 12 through a bench or support 17 herein shown with legs 18 and 19'.

The anvil portions5 and 6 are diametrically opposing segments conforming approximately .to-the curvature of the riddle sides or. annulus 20, the ends of which are beveled portions 21' and 22 which overlap each other over the upper anvil 5 where they are adapted to be nailed or otherwise secured together to form a substantially unbroken annulus. The latter .is held clampedin its ring-form during such fastening of the overlapping beveled ends bymeans of oppositely movable clamp members and 25 engaging. the'outer sides of the cylinder on form and similar inner clamp members and 2? which engage theinner periphery of said form. The members of each pair of clampmembers are moved by means of toggle links actuated through said rod. 11. Said links are placed opposite an opening. 28

in the plate 2 to permit projection of the links to both the inner and outer; clamp members.- To the pair of outer and inner clamp members 24 and 26 are, respectively, pivoted links 29 andBO, the formers pivot being in an enlargement 31 on the upper portion of the clamp member 24. The inner end. of the link 291s pivoted at 32 to one end of a link 83 the middle portion of which is expanded and bored to receive-the rod 11 as shown best in Figure 3. To. the opposite end of said link 33 is pivoted: the inner end of a link 35 the outer end of which is pivoted at 36 to the clamp member 25. The inner pivots for the toggle links extend to both front and rear of the opening 28, the toggle links for the outer clamp-members passing back of the plate 2 while the toggle links for the inner members pass in front of said plate 2, as indicated in all the views. The links for forcing the inner clamp members 26 and 27 toward or away from the outer clamp members include said link 30 and a similar link 37, which are respectively pivoted at 38 and 39 to the inner clamp members and pivoted at 40 and 41 to a connecting link 42, similar to the link 33 in form and engagement with the rod 11. The links 33 and 42 are adjustably secured to said rod 11 for adjustment toward and from each other, or for varying the normal space between the co-operating pair of clamps 24 and 26 and 25 and 27, by means of nuts 43 and 44 which have threaded engagements with said rod ll and operate against opposite sides or edges of the link 42. Similar nuts 45 and 46 are adapted to adjust the link along the rod 11 in the same manner.

The lower ends of the four clamp members are pivoted to the back-plate 2, or to boss or lug extensions thereon. The said pivot for the clamp-member 24: is indicated at 47 and that for the member 25, at 48. The back-plate pivots for the inner clampmembers 26 and 27 are shown at 4:9 and 50. Between the latter are back plate projections 51 and 52 following the curvature of the anvil portion 6 and together with it forming trough-like recesses to engage the lower portion of the drum or cylinder 20 or to assist in positioning said work 20 and, in connection with the clamp-members, to

hold the work, or 20, while being nailed or secured as at 23 where the nails 23 are shown driven from the outside against the anvil portion 5. The clamps are then released and the joint 2122 placed over the anvil portion 6 to be additionally secured by driving nails from the inside against the anvil 6, as suggested by dotted lines to the right in Figure 1.

Having thus described my invention, 1 claim as new and desire to secure by Letters Patent- 1. A drum-forming machine of substantially annular form, which form consists of a series of clamp-members movable toward and from each other, and a pair of diametrically arranged immovable auvils on inner and outer faces respectively, and means for moving said clamps simultaneously.

2. A drum-forming machine, clampmembers movable inwardly and outwardly which provide a substantially annular space adapted to receive an annulus or cylinder and inwardly and outwardly movable clamp-members between them, a pair of oppositely disposed and stationary anvils, and means for contracting said space.

3. A drum-forming machine consisting of a series of movable clamp-members, one pair thereof adapted to engage the inner periphery of a drum or cylinder expan sively, while another pair thereof is adapted to engage the outer periphery of said. drum or cylinder contractively, a levermechanism connecting said clamp-members to move co-operatively, and a pair of anvils engaging, respectively, the outer and the inner peripheries of said drum or cylinder, said anvils being arranged in a plane passing substantially between said clampmembers.

4:. In a drum-forming machine, the combination of an upper with a lower support for, respectively, an inner and an outer portion of the peripheries of a drum or hollow cylinder, of curved and movable clamps adapted to engage therebetween opposite sides of said drum or hollow cylinder, and means for operating said clamps simultaneously.

5. The combination with oppositely moving and co-operating clamps arranged to form a substantially annular recess to enclose an open ring or annulus, of means for moving said clamps to contract said recesses and clamp said work between said clamps, and anvils on which the ends of said ring or annulus are nailed together.

6. The combination with a back plate, of oppositely disposed pairs of clamps mow able toward and from each other and forming therebetween a substantially annular recess adapted to receive work in the form of a drum or hollow cylinder, of diametri cally disposed nailing anvils adapted to support inner and outer portions of said. work, and means for moving said clamps to grip said work.

In testimony whereof I have hereunto signed my name.

FRIDOLF r. BACKSTROM. 

